from pptx import Presentation

prs = Presentation("existing.pptx")

for slide in prs.slides:
    for shape in slide.shapes:
        if shape.has_text_frame:
            for paragraph in shape.text_frame.paragraphs:
                for run in paragraph.runs:
                    if "old text" in run.text:
                        run.text = run.text.replace("old text", "new text")

prs.save("modified.pptx")

from pptx import Presentation

prs = Presentation("presentation.pptx")

for slide_num, slide in enumerate(prs.slides, 1):
    print(f"\n--- Slide {slide_num} ---")
    for shape in slide.shapes:
        if shape.has_text_frame:
            for paragraph in shape.text_frame.paragraphs:
                print(paragraph.text)

from pptx import Presentation
from copy import deepcopy

prs = Presentation("source.pptx")
# Note: python-pptx doesn't directly support slide copying
# Use slide layouts from the same presentation instead